Answer:
x = 50
Explanation:
Since the two angles are opposite each other, you know that they are equal.
Set both equations equal to each other to isolate x:
2(x + 10) = 3x - 30
Distribute 2 on the left side
2x + 20 = 3x - 30
Subtract 2x from both sides
20 = x - 30
Add 30 to both sides
50 = x